PHILADELPHIA, Pennsylvania — The City of Brotherly Love lived up to its name this week, thanks in part to a group of people the Democratic Party couldn’t quite bring itself to thank properly: the men and women of law enforcement. Police were everywhere — on street corners and in subways, on bicycles and on Independence Mall. They were consistently friendly, augmented by a small army of local volunteers who helped steer visitors to and from the Democratic National Convention safely. But the convention struggled to acknowledge police at all. As former New York mayor Rudy Giuliani noted, there were no uniformed law enforcement personnel seen on the floor of the Wells Fargo Arena, likely out of fear that left-wing delegates — many of whom wore “Black Lives Matter” T-shirts, pins and paraphernalia — would protest. Indeed, that is exactly what happened on the last day of the convention, when the Democratic Party finally held a moment of silence to remember fallen officers — and Black Lives Matter activists interrupted it. The convention had passed up the opportunity to honor the officers two days before, when it had the “Mothers of the Movement,” women who lost sons or relatives in confrontations